ARLINGTON, Texas — After the clock had run out and “Carmen Ohio” had been sung and the Ohio State Buckeyes made their way off the field at AT&T Stadium, nobody paid much attention to Ryan Day.

Thousands of Ohio State fans were cheering for the players as Day walked off, laminated play sheet in his left hand and black ball cap on his bowed head. Day did nothing to call attention to himself, and nobody shouted out to him. The coach with the best winning percentage in school history (3-0) was already transitioning back to anonymity.

But once he made his way into the tunnel toward the locker room, that changed. Defensive tackle Haskell Garrett caught up with Day, draped an arm around his shoulders and said some words. Then tight end Rashod Berry did the same. Day had guided them through a tumultuous August and first half of September, and they wanted to thank him.

Day’s run as interim coach at Ohio State ended here Saturday night. It ended with a perfect record, capped off by a 40-28 victory over TCU that was marked by the first in-game adversity the Buckeyes have faced this season. On a night when Ohio State’s best player, Nick Bosa, finished the game in street clothes with an injury, and the Buckeyes trailed by eight points in the third quarter, they rallied and won going away.

Back from university-imposed exile, Urban Meyer will take it from here. But first, Buckeye Nation owes some applause to Ryan Day.

Thrust into a high-pressure situation and replacing the second-best active coach in college football, the previously low-profile Day did his job. In a thankless position where the blame associated with an upset loss would far exceed the credit given for expected wins, he kept the season on track.

And then, when this game was over, he allowed himself to exhale.

“I do feel a little bit of relief now,” Day acknowledged.

He thanked defensive coordinator Greg Schiano and co-offensive coordinator Kevin Wilson for their help. Both had previously been head coaches, but Ohio State entrusted the program to the 39-year-old Day.

“I got so much help from these players and the coaching staff,” Day said. “What Greg Schiano did for me in the last month is something I’ll never forget. He’s the classiest person I’ve ever been around in the coaching profession. The way he’s handled himself, helping me along the way, counseling me on day-to-day stuff. … So, yeah, a little bit of relief, but still got a long way to go here.”

A long way to go in a Big Ten that has diminished itself weekly. After a preseason of hype and high ratings, Ohio State vs. Penn State on Sept. 29 now looks like it could be one of the few marquee games on the league’s schedule.

From that standpoint, Day’s ability to get through the first 25 percent of the regular season without a disaster was all the more noteworthy. There have been so many other pratfalls around the conference.

Asked to grade Day’s interim performance, quarterback Dwayne Haskins said, “Is there an A-plus-plus in the grade book?”

Of course, it’s easier to ace football tests when you have all the necessary athletic answers. Ohio State hit TCU with a series of game-breaking plays that showcase the team’s elite talent level — especially on the defensive line, which often is the differentiating position between true national contenders and pretenders in college football.

Midway through the first quarter, with TCU backed up in the shadow of its own goal line, Bosa came roaring off the edge and knocked the ball loose from Horned Frogs quarterback Shawn Robinson. Ohio State tackle Davon Hamilton fell on it in the end zone for a touchdown.

In a season flush with dominating defensive linemen, Bosa might be the best of the bunch. His brother, Joey, was the No. 3 pick in the 2017 NFL draft, but a lot of people think Nick will be better. That play showed why.

But Bosa wasn’t the only Ohio State defensive lineman capable of jaw-dropping athleticism. In the third quarter, tackle Dre’Mont Jones sniffed out a TCU shovel pass from Robinson to running back Sewo Olonilua and intercepted it. Then the 286-pounder galloped 28 yards for the touchdown, running like someone 50 pounds lighter.

Haskins suggested that Jones could be due for some playing time at fullback after that jaunt.

Between those two defensive scores, Ohio State got its other game-breaking play. A short pass to receiver Parris Campbell turned into a 63-yard touchdown — the Buckeyes’ first offensive touchdown of the game.

Coming into this game, TCU led the nation in allowing the fewest scrimmage plays allowed of 10 yards or longer, at 5.5 per game. Eight different Ohio State players had double-digit runs or receptions, with Campbell’s catch and run being the longest.

The Buckeyes needed almost all of them to win this game, because they were pushed. TCU hit them with three different pass plays longer than 30 yards, and also a 93-yard rushing touchdown — the longest run in TCU history and the longest run ever allowed by Ohio State.

After two milk runs against overmatched Oregon State and Rutgers, the Buckeyes found themselves in a battle Saturday night. The interim coach was under real pressure. And he handled it perfectly.

Ryan Day will recede from the spotlight again now, relieved to be doing so. But it’s nice to go out undefeated.

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